This PR includes a more robust (and slightly more accurate) method for reading the black levels from the DNG.
Certain older cameras (e.g. Canon 350D) which previously did not load correctly are now supported.
X-Trans sensors now have their black levels read. (exposure merging has not been enabled for them, that will be a seperate PR once we get some testing images).
Demosaiced (or Foveon images) are still not supported.
Added support for manually calculating black levels from masked areas (if the DNG specifies any) as a fallback option.
DEV: Command Buffers have been labeled to make debugging the metal code easier
This PR includes a more robust (and slightly more accurate) method for reading the black levels from the DNG.